Lawn trimmer and edger



Oct. 13, 1953 A,

LAWN TRIMMER AND EDGER 2 Sheets-Sheet 1 Filed March 21, 1949 ll ill L flrtharE/lliller,

ATTOX:

Oct. 13, 1953 A. E. MILLER LAWN TRIMMER AND EDGEIR 2 Sheets-Sheet 2 Filed March 21, 1949 flrthurEfliZZer,

ATTO EY fatenteci Oct. 13,

UNITED STATES PATENT OFFICE 2,654,985 LAWN TitiiviMER ifieiiiit Itiiiler, Milwaukee, Wis. iiiipliati'm Marsh 21, 19455, sir'iai lifoiifs it 7 Claims.

The invention rlzrtes' to lawn triniiners an the machine disclosed and clai med irr rny prior @fiblication see-a1 N01 71%,Q35 filed December},

These machines are of a v relatively narrow, light-Weight manueHy operg-ted type especially idepted for trirfifiirig the edge portions of la'wns along walks; pavements; ccpings; flower beds, etc., tether than for cutting t fiegrass in the body por tion of the lawn, and they comprise an oscillatory shear device normaiiy'opiereting in a" substantially hdriz'ontal pleine at irontof the machine, which shear is 1 by calnrg carriedby a single sujjborting wheedisposed toward the rear The shear ofieretes quite close to' the ground surface arid is' carried by a" frame which mounts the Wheel :i-xle and is vertically swingla ble about the axis thereof, whereby: theshelar may rise and fall to follow uiiereniiesses' saidsurfaice. The handle by iiieans of which the machine is traversed over the ground extends to we rear end is pivotally mounted on these axle independently of the shear fratme' so that the latter may rise and fell Without corres fi'ondirfg more'ments' of the handle.

Itis one of the ohj'ect'sof the present inventionto provide an unmoved shear construction and a'jz'iimproved} drive for the oscilietory shear blade of a-metdhihe of the-type above described; I W

A further object of the invefitionis toprovi-de amachine for trfnimihg the edge portions of lawns having; in eddi'tionto the horizontally op er'atihgshear m chanisma' rotatable disk cutter adapted-to functionirr 9; vertical plane along the edges of Walks, anines; eta,- w hi'c h disk is so mounted on-th eaegmgmm as to occupy an elef vat'ed' inofierative p'qsit'ic'ri when the shear is inf its nor'nialfunctioning position; The edger disk:

however; niey be e sily brought to on operative position by merely the sheer frame up warcuy about the axle to art elevatedrearward position above the handle, which movement lowers the edger disk into ground engig'enifnt for travers'e'in= contact with-0r proximity to the' edge of a} paveniehtQcbIiihgbr the lik'er In"' this pcsi tion the disk axis is so disposedrelative tothat' of the'suppoftin'g wheel that the force exerted by the" operator on' the htfidleflin treversingf the 111 chine over the ground tehd'sto preterit the sheer frame from swinging back" to its nor'rrial oesttion.

Other objects will appear as the description proceeds. 7 v U Atypical embodiment of the ihven'tion mums trated' in the accompanying dre'vtings" forrhinga part of this specification} whr'ein like reference characters designate like pare ih air the views-,-

and in which: o Figure 1' isei; side elvtioriihiitv dfihrhathe fixedsheer beat; is re a 2 t in; new w th t e sh ar frame and shear shown in their normaii operating P tions; A V Fig. Zjsji plat! View ther'of, on 9'. somewhat lergrscale; I h

311g. 3 is a; veneer s le 2, ifi 3 3 iij1 Fig. 1; lookin arrows;

ch retains the. libbrs or movable shearhlafdef in position, and transmits oscillatory movement thereto;

(see Fig. 3) and a tubular handle 28 is rigidly secured to the medial portion of said member, from which it extends upwardly and rearwardly, as clearly shown in Fig. l. The upper end of said handle may be provided with a rubber or similar grip 29.

Also journaled on the spacing sleeve 26, between the legs of the handle member 21, is the hub 30 of the supporting and actuating wheel 3|. To the medial portion of said hub there is welded or otherwise rigidly secured a circular plate 32 which is stamped to serpentine conformation to provide a series of circumferentially spaced undulating cams 33 alternating to each side of the center plane of the wheel. The serpentine plate is surrounded by and rigidly secured to a rim 34 upon which is mounted a resilient tire 35.

The cross member I! of the shear frame has an upstanding stud 36 rigidly secured to it, which stud journals the bearing sleeve 3'! of an elongated plate-like actuating member 38, a nut 39 threaded on the upper end of the stud serving to retain said member in position. The rearward portion of the actuating member 38 is bifurcated, providing a pair of legs 40 which straddle the supporting wheel 3| and extend chordally alongside the lower sector thereof, as shown in Figs. 2 and 3. A block 4| of hard or vulcanized fiber and of substantially the shape shown in Fig. 11, is secured to the rearward end of each leg 43, with the opposed tips of the blocks being spaced apart substantially the thickness of the wheel disk 32 and engaging the opposite faces of its undulatory earns 33, whereby upon rotation of the wheel oscillatory motion will be transmitted to the actuating member 38.

The parts are so proportioned that the tips of the blocks 41 engage the wheel cams on a radius thereof which is perpendicular to the plane of oscillation of the actuating member 38; in other words, directly below the axle when the machine is in its normal operating position on level ground, as shown in Figs. 1 and 5. By so locating the blocks all tendency of the wheel cams to impart an upward or downward thrust component on the actuating member is eliminated. In prior machines of this type wherein the cam followers have been located either forwardly or rearwardly of the vertical plane of the wheel axis, it has been found that the upward or downward thrust imparted to the actuating member by the cams tends to cant the member upon its pivot and thus greatly accelerates wear thereon. This soon progresses to a stage where the engagement between the shear blades is impaired to the point that their shearing action is so erratic as to make it necessary to traverse each section of the lawn several times in order to secure a satisfactory cut. Also, with the shear frame free to rise and fall as here and with the cam followers engaging the cams forwardly of the wheel axis, when drawing the machine backward preparatory to making another traverse, the upward thrust component has been sufficient to cause the shear frame to flop up and down violently and noisily. But by so locating the follower blocks 4| as to contact the wheel cams 33 in the vertical plane of the wheel axis, all thrust imparted to the actuating member 38 is in horizontal directions (either lateral or fore-and-aft) which in no wise affect the shear tension or operation, or tend to cause any flopping of the shear frame.

A flat spring 45, of the shape best shown in Fig. 10, is secured to the forward end of the actuating member 38 by rivets 46. The forward portion of this spring is provided with a pair of laterally spaced apertures 41, and the medial portion of the forward edge of the spring is provided with a downward projection or car 48 adapted to contact the medial portion of the upper surface of the oscillatory shear blade 49 at a single point. As best shown in Fig. 12, this blade has a plurality of forwardly extending radiating teeth 50, and its body portion rigidly carries a pair of transversely spaced upstanding pins 5| which are adapted to be freely slidably received in the apertures 41 of the spring member 45, as shown in Figs. 1,2,5 and 6.

The rearward portion of the movable blade 49 rests upon and freely slides over the upper surface of the raised boss 23 carried by the lower fixed blade 20. The said boss is of such height as to give a slight forward inclination to the upper blade 49 and as the latter is continuously pressed downwardly by the spring 45 it results that when the teeth 50 of the movable blade are intermediate those of the fixed blade, as shown in Fig. 2, the said teeth 50 incline somewhat into the spaces between the teeth 22 of the lower blade. As the upper teeth move into alinement with the lower ones the spring 45 yields to enable the forward portions of the teeth 50 to rise and slide over the lower teeth, and during this action the shearing edges of the two sets of teeth are maintained in intimate contact throughout their length, producing a true and effective shearing action.

While the boss :2 3 is here shown as being carried by the lower blade 20, obviously it might be formed on and project downwardly from the upper blade, with the upper surface of the lower blade being flat; or, complemental bosses might be formed on the two blades.

The upper blade 49 is maintained in position on the lower blade 20 solely by the downward pressure of the spring 45, and the pin connections 5| between the said spring and upper blade serve not only to transmit oscillatory motion to the blade from the actuating member 38 but also to prevent slueing of the blade from longitudinal alinement with the actuating member. The one point medial contact between the spring and upper blade, provided by the ear 48 of the spring, coupled with the support of the rear portion of the blade on the raised bearing boss 23, and the sliding fit of the pins 51 in the spring apertures 41, all combine to provide a full floating mounting of the blade 49 which enables it to accommodate itself not only to slight manufacturing irregularities in the teeth of either blade but also, within limits, to actual bending or misalinement of the teeth resulting from their striking stones, copings or other hard obstructions in the use of the machine.

The respective shear blades are in themselves fairly rigid, being stamped from sheet metal of about one-eighth inch in thickness and subsequently hardened and ground. The dies which remove the metal from between the blade teeth 22 and 50 are so formed and function in the course of the stamping operation as to produce raised flanges or lands 52 along the edges of the teeth (see Figs. 2, 8 and 9), and by flat grinding the surfaces 53 of these flanges it is possible to produce sharp even cutting edges on the teeth, both in the course of manufacture and in resharpening the teeth after use, more easily and efficiently than by grinding the tooth faces 54, as is common practice.

The force exerted by the spring 45 on the .5 blade 49 maybe readilyvaried byadiustment of the nut. 38 on the pivot stud 36, to secure the most effective shearing action.

Althou h the shear frame. l5 and the. handle 28 are independently swingable about the wheel axis, so that the frame may freely rise and fall to follow unevennesses .in the ground; surface with.- out corresponding movements of the handle, it is. desirable to interengage them at a certain point in their angular relationship to one another in orderthat by depressing the handle'the frame may be elevated to. enable the. shear to clearan unusual obstruction. The point of coupling should be somewhat variable. so that the handle may be disposed at the inclination best suited to the height of the operator, and a simple but effective means. has been provided whereby to readily vary the point of interengagement as occasion may require.

As best shown in Figs. 1 and 4, this means comprises a rectangular block 55 pivotally mounted on the inside of one of the frame side plates 16 in position for its edge faces to be engaged by a leg of the U-shaped handle member 21. The pivot 56 passes through the block eccentrically thereof so that each of the four edge faces of the block is at a different distance from the axis of the pivot. By manually moving the block about the pivot to present different edge faces thereof for engagement by the leg of the handle member 21, the angular relationship of the handle to the shear frame at the time of engagement may be varied, as indicated in Fig. 4, wherein two of the positions are illustrated in full and broken lines respectively. A spring washer 51 is interposed between the block and the head of the pivot 58, to provide sufficient friction to hold the block in any set position against unintentional displacement therefrom.

A further feature of the machine resides in the provision of a supplemental edging cutter mounted upon the shear frame l5 in a special manner, and usable to sever grass overgrowing the edges of walks, copings, etc. This cutter comprises a sharpened disk 60 journaled upon a; stud 6| carried by an angle bracket 62 which is welded or otherwise rigidly secured to one of theside plates I5 of, the frame, adjacent the edge thereof: When the frame is in its normal position for operation of the shear mechanism the disk 60 occupies an elevated inoperative position toward the rear of. the machine, as shown in Figs. 1, 3 and 6. When it is desired to out blades of grass occupying a more or less horizontal position and extending over the edge of a pavement or coping, the frame I5 is swung upward about the wheel axle 25 to a rearwardly and upwardly inclined position above the handie structure, thuslowering the edging disk 60. into engagement with the ground, as shown in Fig. 7, The machine is then traversed with the disktll in engagement with or proximity to the side of the coping or pavement, and its cutting, edge severs the horizontal grass blades. The parts, are so proportioned that when the frame [5 is in this position the machine is supported solely by the edging cutter 60, with the wheel 31 out of ground engag ment, and thus when the machine is traversed the said wheel will not be, rotated nor the shear mechanism operated.

Thebracket 62 is so positioned on the frame 45 that when the parts are'in the Fig, 7 positions, thestud 6| which Journals the edging disk 60. is located forwardly of the wheel axle 25, which, is thepivot about which the frame I5 swings. It results from this disposition of the edging disk that the weight of the machine plus the downward force exerted by the operator through the handle 28 tend to turn the frame in a clockwise direction about the axle 2-5, the effect of which is to maintain the end of the pivot stud 36 jammed against the handle 28 and prevent the frame from flopping upand down or even being kicked over to its normal shearoperating position.

While one form of the invention has been illustrated and described, it will be apparent that variations may be made in the details of construction and precise arrangement of parts without departing from the spirit of the invention, and therefore it is not wished to be limited to the above disclosure. except as may be required by the claims.

What is claimed is:

1. In a machine for trimming the edge por tions of lawns, the combination of a groundengaging wheel provided with a series of circumferentiallyspaced' cams; an axle journaling said wheel; a shear frame mounting said axle and having a horizontal member disposedv forwardly of the wheel; a toothed shear blade fixedly carried by and extending forwardly from said horizontal frame. member; a second toothed shear blade floatingly superposed upon said fixed blade; an actuating member disposed above and pivotally mounted upon said horizontal frame member, the rearward portion of said actuating member being provided with clefments engaging said wheel cams whereby hori-'-- zontal oscillation may be imparted to the actu-- ating member through rotation of the wheel; a fiat spring fixedly carried by and extending forwardly from said actuating member and having a portion pressurally contacting the upper surface of the floating shear blade at a single medial point whereby to maintain yieldable engagement between the teeth of the two blades; and non-rigid connections between the spring and floating blade maintaining the. latter in proper position andtransmitting oscillatory mo tion thereto from the spring and actuating. member.

2. In a machine for trimming the edge portions of lawns, the combination of a ground-engaging wheel provided witha series of circumferentially spaced cams; an axle journaling said wheel; a shear frame mounting said axle and having a horizontal member disposed forwardly of the wheel; atoothed shear blade fixedly car.- ried by and extending forwardly from said horizontal frame member; a. second toothed. shear blade fioatingly superposed upon said fixedblade and provided with a plurality of spaced. upstanding pins; an actuating member disposed. above and pivotally mounted upon said horizontal frame member, the rearward portion of: said actuating member being provided with elements. engaging said wheel cams whereby horizontal. oscillation may be imparted to the actuating member through rotation of the wheel; and a:

flat spring fixedly carried by and extending for-- wardly from said actuating member and pressurally engaging the upper surface of the floating shear blade at a single medial point where-- by to maintain yieldable engagement between the teeth of the two blades, said spring also having'a plurality of spaced apertures slidably re ceiving the pins of said floating shear blade;

3; Ina machine for trimming the-edge portionsof lawns, the combination of a ground-engaging wheel provided with a series of circumferentially spaced cams; an axle journaling said wheel; a shear frame mounting said axle and having a horizontal member disposed forwardly of the wheel; a toothed shear blade fixedly carried by and extending forwardly from said horizontal frame member; a second toothed shear blade floatingly superposed upon said fixed blade; a boss on the rear portion of one of said blades providing a sliding bearing for the complemental portion of the other blade and imparting a forward downward inclination to the floating blade; an actuating member disposed above and pivotally mounted upon said horizontal frame member, the rearward portion of said actuating member being provided with elements engaging said wheel cams whereby horizontal oscillation may be imparted to the actuating member through rotation of the wheel; a fiat spring fixedly carried by the forward portion of said actuating member, said spring being provided with a medial downward projection pressurally contacting the upper surface of the floating shear blade at a single medial point whereby to maintain yieldable engagement between the teeth of the two blades; and nonrigid connections between the spring and floating blade maintaining the latter in proper position and transmitting oscillatory motion thereto from the spring and actuating member.

4. In a machine for trimming the edge portions of lawns, the combination of a ground-engaging wheel provided with a series of circumferentially spaced cams; an axle journaling said wheel; a shear frame mounting said axle and having a horizontal member disposed forwardly of the wheel; a toothed shear blade fixedly carried by and extending forwardly from said horizontal frame member; a second toothed shear blade floatingly superposed upon said fixed blade and provided with a plurality of spaced upstanding pins; a boss on the medial rear portion of one of said blades providing a sliding bearing for the complemental portion of the other blade and imparting a forward downward inclination to the floating blade; a horizontal longitudinally 'extending actuating member pivotally mounted on said frame member, the rearward portion of said actuating member being provided with cam followers engaging said wheel cams whereby horizontal oscillation may be imparted to the actuating member through rotation of the wheel; and a flat spring fixedly carried by and extending forwardly from said actuating member, the forward edge portion of said spring being provided with a medial downward projection pressurally contacting the upper surface of the floating shear blade at a single medial point whereby to maintain yieldable engagement between the teeth of the two blades, said spring also having a plurality of spaced apertures slidably receiving the pins of said floating blade.

5. In a machine for trimming the edge portions of lawns, the combination of a ground-engaging wheel provided with a series of circumferentially spaced cams; an axle journaling said wheel; a traversing handle journaled on said axle; a shear frame mounting said axle and swingable about the axis thereof relative to said handle, said frame having a portion extending forwardly of the wheel; a toothed shear blade fixedly carried by said forwardly extending portion of the frame; a second toothed shear blade movably superposed upon said fixed blade in shearing engagement therewith; a longitudinally extending actuating member pivotally mounted upon said shear frame for horizontal oscillatory movements, the rear ward portion of said actuating member extending chordally of the wheel laterally adjacent the cammed portion thereof and having cam engaging elements contacting the cams on a radius of the wheel which is normal to th plane of oscillation of said actuating member, whereby the cams impart only horizontal thrust to the actuating member thus substantiall preventing vibrations of the shear frame relative to said handle; and driving connections between said movable shear blade and the actuating member whereby the latter may oscillate the former.

6. In a machine for trimming the edge portions of lawns, the combination of a ground-engaging wheel provided with a series of circumferentially spaced cams; an axle journaling said wheel; a shear frame mounting said axle and swingable about the axis thereof, said frame having a horizontal member disposed forwardly of the wheel; a toothed shear blade fixedly carried by and extending forwardly from said horizontal frame member; a second toothed shear blade floatingly superposed upon said fixed blade; a longitudinally extending bifurcated actuating member disposed above and pivotally mounted upon said horizontal frame member, the legs of said actuating member straddling the lowest sector of said wheel; a cam engaging element carried by each leg of said actuating member, the cam contacting portions of said elements being disposed on a radius of the wheel which is normal to the plane of oscillation of said actuating member, whereby the cams may impart horizontal oscillatory movements to the actuating member without upward or downward thrust components; a flat spring fixedly carried by and extending forwardly from the actuating member and pressurally contacting the upper surface of the floating shear blade at a single medial point whereby to maintain yieldable engagement between the teeth of the two blades; and driving connections between the spring and the floating shear blade for transmitting the oscillatory motion of the actuating member and spring to said blade.

7. In a machine for trimming th edge portions of lawns, the combination of a ground-engaging cam carrying wheel; an axle journaling said wheel; a shear frame having side plates mounting said axle, said frame being swingable vertically about the wheel axis; shear mechanism carried by the frame forwardly of the wheel and operable by the cams thereof; a rearwardly inclined traversing handle pivotally mounted by the axle and swingable thereabout independently of the shear frame; and a block having a plurality of edge faces, said block being pivotally mounted on one of the frame side plates in position for said edge faces to be engaged by a portion of said handle, the pivot of said block being eccentric thereof so that the several edge faces of the block are unequally spaced from the pivot, whereby by turning the block to present different edge faces for engagement by the handle the angularity of the latter relative to the frame may be varied.

ARTHUR E. MILLER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,071,110 Stover Aug. 26, 1913 1,654,574 Brown Jan. 3, 1928 1,770,434 Schlicher July 15, 1930 2,484,795 Schofield Oct. 11, 1949 2,503,343 Miller Apr. 11, 1950 2,574,947 Allen Nov. 13, 1951 

